In the history of video game tennis simulations, Nintendo's Tennis was perhaps advanced for its time, and maybe even had some key role in the evolution of the genre. I wouldn't know, because I don't really care. Looked at now it is simply a frustrating game with sloppy play control, and offers almost no compelling reason to play.
There are no tournaments, rankings, any of the niceities you may have come to expect from modern tennis games. Single player mode puts you in the shoes of Generic Yuppie Guy #1, you face off against a series of five other Generic Yuppie Guys (identifiable solely by wearing different colored shirts) who progress in difficulty from "You might win if you have enough patience to adjust to the nuances of these sloppy slidey controls" to "IT' TOO EARLY TO FEEL SAFE!!! I'LL KILL YOU HERE!!!". Each match is played out on the same sparse clay court. When you beat them all you get ... to start over from the beginning.
There's a doubles mode, which is the only faintly interesting thing about the game, and that's only because after every point the game gives you a few seconds to run around like loons and try to come up with bizarre victory dances.
* Gameplay Video